Press forming method and press forming device

Abstract

To provide a press forming technique effective to improve the material yield of a metal blank.SOLUTION: In a press forming method, a metal blank 1 is formed into a panel. According to the press forming method, while one end 1a of both ends 1b, 1a in a width direction X of the metal blank sheet 1 is sandwiched by a die 20 and a blank holder 30, and the other end 1b is sandwiched by a first member 51 and a second member 52, the first member 51 and the second member 52 are integrally slid in a pulling direction X1 and then slid in a pulling-back direction X2 opposite to the pulling direction X1; and the die 20 is moved toward a punch 10 in a press forming direction Y in parallel with the sliding of the first member 51 and the second member 52 in the pulling-back direction X2 to form the metal blank sheet 1 into the panel 2 by means of the die 20 and the punch 10.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a press forming method and a press forming apparatus.

Background Art

[0002] The following Patent Document 1 discloses a conventional drawing forming method. In this drawing forming method, the outer edge portion of a metal blank is gripped by the outer peripheral portion of a die and a wrinkle presser portion, and while applying tension to the metal blank through a draw bead, a punch and a die approach each other to draw and form the metal blank into a predetermined shape.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a forming method in which a metal blank is simply stretched as it goes, like the drawing forming method disclosed in Patent Document 1, it is common to leave a margin in the sheet thickness reduction rate at the end of forming so that elongation cracks do not occur. That is, in the conventional method, the actual sheet thickness reduction rate is set to be significantly lower than the limit value of elongation cracks, leaving a margin for the elongation of the metal blank. In this case, although the sheet thickness reduction rate of the metal blank could originally be increased as much as possible, there is a problem that the metal blank cannot be fully utilized and the material yield is low by leaving a margin for the elongation of the metal blank. Therefore, in this type of press forming technology, there is room for improving the material yield of the metal blank.

[0005] The present invention has been made in view of such problems, and aims to provide a press forming technology effective for improving the material yield of a metal blank.

Means for Solving the Problems

[0006] One aspect of the present invention is a press forming method for forming a metal blank into a panel, using a punch, a die provided opposite to the punch, a blank holder provided opposite to both end portions in the width direction of the die, a first member slidably provided on the die in the width direction, and a second member slidably provided on the blank holder in the width direction, with one end portion of both end portions of the metal blank being clamped between the die and the blank holder and the other end portion being clamped between the first member and the second member, sliding the first member and the second member integrally in the tensile direction and then sliding them in a pulling-back direction opposite to the tensile direction, and moving the die in the press forming direction toward the punch in parallel with the sliding of the first member and the second member in the pulling-back direction or after the sliding in the pulling-back direction is completed to form the metal blank into the panel with the die and the punch. is as follows.

[0007] Another aspect of the present invention is a press forming apparatus for forming a metal blank into a panel, including a punch, a die provided opposite to the punch, a blank holder provided opposite to both end portions in the width direction of the die, a first drive mechanism unit for moving the die in the press forming direction, a first member slidably provided on the die in the width direction and a second member slidably provided on the blank holder in the width direction, and a second drive mechanism unit for sliding the first member and the second member integrally in the tensile direction and then sliding them in a pulling-back direction opposite to the tensile direction with one end portion of both end portions of the metal blank being clamped between the die and the blank holder and the other end portion being clamped between the first member and the second member, and a control unit for controlling the first drive mechanism unit and the second drive mechanism unit, is provided. The control unit moves the die toward the punch in the press forming direction by the first drive mechanism unit in parallel with the sliding of the first member and the second member in the pulling-back direction by the second drive mechanism unit or after the sliding in the pulling-back direction is completed, and forms the metal sheet into the panel with the die and the punch, a press forming apparatus. is in.

Advantages of the Invention

[0008] In the press forming method or press forming apparatus of the above-described aspect, first, while one end portion of the metal sheet is clamped between the die and the blank holder and the other end portion of the metal sheet is clamped between the first member and the second member, the other end portion of the metal sheet is pulled in the tensile direction by the first member and the second member. As a result, the metal sheet is stretched in the tensile direction as a whole by plastic deformation. Then, while the other end portion of the metal sheet is still clamped between the first member and the second member, the other end portion of the metal sheet is pulled back in the pulling-back direction opposite to the tensile direction by the first member and the second member. And, in accordance with the timing of pulling back the other end portion of the metal sheet, or after pulling back the other end portion of the metal sheet, the die is moved in the press forming direction toward the punch. Thereby, the metal sheet is formed into the panel with the die and the punch.

[0009] According to the press forming method or press forming apparatus of the above-described aspect, after intentionally stretching the metal sheet as much as necessary and possible in the initial stage of forming, substantial press forming by the die and the punch can be performed. Thereby, compared with the conventional method in which the metal sheet is simply stretched by chance during press forming, the metal sheet can be stretched in the initial stage of forming by effectively using the extra elongation allowance, and the sheet thickness reduction rate of the metal sheet can be increased. Therefore, the size of the panel after press forming can be increased for a metal sheet of a predetermined size, or the size of the metal sheet for obtaining a panel of a predetermined size can be reduced. Thereby, the material yield of the metal sheet is improved compared with the conventional method.

[0010] As described above, according to each of the above-described aspects, it becomes possible to improve the material yield of the metal sheet.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Mode for Carrying Out the Invention

[0012] Preferred embodiments of the above-described aspects will be described below.

[0013] In the press forming method or the press forming apparatus of the above-described aspect, it is preferable that the first slide amount in the tensile direction and the second slide amount in the pulling-back direction of the first member and the second member are the same. By making the first slide amount and the second slide amount coincide, the control related to the slide of the first member and the second member can be simplified.

[0014] In the press forming method or press forming apparatus of the above-described embodiment, it is preferable to set the first slide amount based on the management reference value of the plate thickness reduction rate during the press forming of the metal blank. By setting the first slide amount based on the management reference value of the plate thickness reduction rate of the metal blank, the actual plate thickness reduction rate of the metal blank can be adjusted to a desired level.

[0015] Hereinafter, specific embodiments of the above-described embodiment will be described with reference to the drawings.

[0016] In this specification and the drawings, unless otherwise specified, the width direction of the die constituting the press forming apparatus is defined as the X direction, and the press forming direction by the die is defined as the Y direction for explanation.

[0017] (Embodiment 1) 1. Overall Structure of Press Forming Apparatus 101 The press forming apparatus 101 of Embodiment 1 shown in FIG. 1 is an apparatus for forming a metal blank 1 into a panel 2 (see FIG. 3) by press forming. A flat plate-shaped metal blank 1 is used. The shape and use of the panel 2 are not particularly limited.

[0018] As shown in FIG. 1, the press forming apparatus 101 mainly includes a punch 10, a die 20, a blank holder 30, a first drive mechanism unit 40, a second drive mechanism unit 50, and a control unit 60.

[0019] In the following description, for convenience, the case where the die 20 is disposed above the punch 10 is exemplified. However, the relative positional relationship between the punch 10 and the die 20 is not particularly limited and can be changed as appropriate.

[0020] The punch 10 is disposed below the die 20. The punch 10 has an opposing surface portion 11 that faces the die 20. The opposing surface portion 11 is the portion that presses the metal blank 1 during press forming. The die 20 is provided to face the punch 10 above the punch 10. The die 20 is provided with a recess 21 into which the opposing surface portion 11 of the punch 10 can be inserted. The blank holder 30 is provided to face both end portions 20a and 20b of the die 20 in the width direction X. The blank holder 30 is supported from below by cushion pins 31. The blank holder 30 functions to sandwich both end portions 1a and 1b of the metal blank 1 in cooperation with the die 20 during press forming of the metal blank 1.

[0021] 2. Structure of the first drive mechanism portion 40 The first drive mechanism portion 40 has a function of moving the die 20 in the press forming direction Y. The first drive mechanism portion 40 includes a slide 41 disposed above the die 20 and a slide drive portion 42 that drives the slide 41 in the vertical direction. Although not particularly shown, the slide drive portion 42 includes a motor and a conversion mechanism (such as a gear, a cam, or a crank) that converts the rotational operation of the motor shaft into the vertical lifting operation of the slide 41. The first drive mechanism portion 40 is controlled by a control portion 60. That is, the motor of the slide drive portion 42 is controlled by a control signal output from the control portion 60.

[0022] 3. Structure of the second drive mechanism portion 50 The second drive mechanism portion 50 includes a first member 51, a second member 52, a cam slider 53, a cam driver 55, a cam base 56, and a cam drive portion 57. The first member 51 is slidably provided on the die 20 in the width direction X. The second member 52 is slidably provided on the blank holder 30 in the width direction X. The first member 51 is provided with an engagement pin 51a, and the second member 52 is provided with an engagement hole 52a into which the engagement pin 51a can be inserted. By inserting the engagement pin 51a of the first member 51 into the engagement hole 52a of the second member 52, the first member 51 and the second member 52 are integrated.

[0023] The second drive mechanism portion 50 has a function of integrally sliding the first member 51 and the second member 52 in the pulling direction X1 and then integrally sliding them in the pulling-back direction X2 while sandwiching one end portion 1a of the both end portions 1a and 1b of the metal base plate 1 between the die 20 and the blank holder 30 and sandwiching the other end portion 1b between the first member 51 and the second member 52.

[0024] The cam slider 53 is integrally connected to the first member 51. The cam driver 55 is provided so as to be in sliding contact with the cam slider 53, and is for moving the cam slider 53 in the width direction X along with the vertical lifting motion. The cam base 56 is for slidably supporting the cam slider 53 in the width direction X. The cam drive portion 57 drives the cam driver 55 in the vertical direction. Although not particularly shown, the cam drive portion 57 includes a motor and a conversion mechanism (such as a gear, a cam, a crank, etc.) that converts the rotational motion of the motor shaft into the vertical lifting motion of the cam driver 55. The second drive mechanism portion 50 is controlled by the control portion 60. That is, the motor of the cam drive portion 57 is controlled by the control signal output from the control portion 60.

[0025] In the second drive mechanism portion 50 having the above configuration, instead of the structure in which the first member 51 and the cam slider 53 are separate parts, a structure in which the first member 51 and the cam slider 53 are one member may be adopted.

[0026] The control portion 60 controls the cam drive portion 57 of the second drive mechanism portion 50 and the slide drive portion 42 of the first drive mechanism portion 40 so as to move the die 20 in the press forming direction Y in parallel with the slide of the first member 51 and the second member 52 in the pulling-back direction X2. For this control, the control portion 60 includes a storage portion 61 that stores control information, and an output portion 62 that outputs a control signal to each of the slide drive portion 42 and the cam drive portion 57 based on the control information stored in the storage portion 61.

[0027] 4. Press forming method The press forming method of Embodiment 1 is a method for forming the metal base plate 1 into the panel 2 using the press forming apparatus 101 configured as described above. In this press forming method, the processes from the first step S101 to the fourth step S104 in FIG. 2 are sequentially executed. Note that, if necessary, another step may be added, or at least one step may be divided into a plurality of steps.

[0028] The first step S101 in FIG. 2 is a step of sandwiching (clamping) both end portions 1a and 1b of the metal base plate 1. As shown in FIG. 3, in the first step S101, the die 20 is moved in the press forming direction Y from the initial position P1 (see FIG. 1) to the first lowered position P2 by the slide drive unit 42. The first lowered position P2 is lower than the initial position P1. As a result, the end portion 1a of the metal base plate 1 is sandwiched from above and below by the die 20 and the blank holder 30, and the end portion 1b of the metal base plate 1 is sandwiched from above and below by the first member 51 and the second member 52. This state is also referred to as a "crimp state". Further, when the die 20 is lowered to the first lowered position P2, the engagement pin 51a is inserted into the engagement hole 52a and engaged, so that the first member 51 and the second member 52 are integrated.

[0029] The second step S102 in FIG. 2 is a step of executing a tensile slide operation of the first member 51 and the second member 52 by the second drive mechanism unit 50. The tensile slide operation is an operation of integrally sliding the first member 51 and the second member 52 in the tensile direction X1. The first slide amount d1 in the tensile direction X1 at this time is preset based on the management reference value Ra of the plate thickness reduction rate R of the metal base plate 1 (see FIGS. 5 and 9). The management reference value Ra is stored in the storage unit 61 of the control unit 60 together with the first slide amount d1.

[0030] As shown in FIG. 4, in the second step S102, the cam driver 55 is lowered from the first position Q1 (see FIG. 3) to the third position Q3 by the cam driving unit 57. In conjunction with the movement of the cam driver 55 at this time, the cam slider 53 slides in the tension direction X1 from the first position R1 (see FIG. 3) to the second position R2. Therefore, the first member 51 and the second member 52 integrated by the pin engagement slide in the tension direction X1 together with the cam slider 53 while sandwiching the end portion 1b of the metal base plate 1 from above and below.

[0031] Here, with reference to FIG. 5, the movement of the cam slider 53 and the cam driver 55 until the second step S102 is completed will be described.

[0032] As shown in FIG. 5(a), the cam driver 55 is provided with a concavo-convex first cam surface 55a on the left side in the width direction X and a concavo-convex second cam surface 55b on the right side in the width direction X. The cam slider 53 is provided with a concavo-convex first cam surface 53a slidable with the first cam surface 55a of the cam driver 55, a concavo-convex second cam surface 53b slidable with the second cam surface 55b of the cam driver 55, and an internal space 54 into which the cam driver 55 can be inserted. When the lower end portion of the cam driver 55 is inserted into the internal space 54, the movement of the cam slider 53 in the width direction X is blocked by the cam driver 55. The cam base 56 is provided with a recess 56a into which the cam driver 55 can be inserted.

[0033] First, the cam driver 55 is lowered from the first position Q1 shown in FIG. 5(a) to the second position Q2 shown in FIG. 5(b) by the cam driving unit 57. At this time, the first cam surface 55a of the cam driver 55 slides with the first cam surface 53a of the cam slider 53, and the second cam surface 55b of the cam driver 55 slides with the second cam surface 53b of the cam slider 53. Then, at the second position Q2, the inclined portion 55a1 of the first cam surface 55a of the cam driver 55 abuts against the inclined portion 53a1 of the first cam surface 53a of the cam slider 53. The second position Q2 at this time corresponds to the "tension start position" where the tension of the end portion 1b of the metal base plate 1 is started.

[0034] The cam driver 55 then descends from the second position Q2 to the third position Q3 shown in FIG. 5(c) by the cam driving unit 57. As the inclined portion 55a1 of the cam driver 55 slides along the inclined portion 53a1 on the cam slider 53 side, the cam slider 53 is slid in the pulling direction X1 from the first position R1 to the second position R2. The third position Q3 at this time corresponds to the "tension completion position" where the tension of the end portion 1b of the metal base plate 1 is completed. As shown in FIG. 5(c), the first slide amount in the pulling direction X1 of the cam slider 53 is d1.

[0035] The third step S103 in FIG. 2 is a step of concurrently performing the return slide operation of the first member 51 and the second member 52 and the press forming operation of the die 20.

[0036] As shown in FIG. 6, the return slide operation is an operation of integrally sliding the first member 51 and the second member 52 in the return direction X2 by the second drive mechanism unit 50. The second slide amount d2 (see FIG. 7) in the return direction X2 at this time is preset and stored in the storage unit 61 of the control unit 60 in the same manner as the first slide amount d1. In this embodiment, the second slide amount d2 is the same as the first slide amount d1. According to this return slide operation, the first member 51 and the second member 52 slide in the return direction X2 together with the cam slider 53 while sandwiching the end portion 1b of the metal base plate 1 from above and below. That is, the first member 51 and the second member 52 return to the positions before the pulling slide operation in step S102.

[0037] On the other hand, the press forming operation is an operation of moving the die 20 from the first lowering position P2 (see FIG. 4) to the second lowering position P3 in the press forming direction Y by the slide driving unit 42. The second lowering position P3 is lower than the first lowering position P2. At this time, the punch 10 enters the recess 21 of the die 20 while pressing the metal blank 1 against the opposing surface portion 11. As a result, the material of the metal blank 1 is pressed by the opposing surface portion 11 of the punch 10 and flows into the recess 21 side of the die 20. Further, the blank holder 30 descends in the press forming direction Y while pushing down the cushion pin 31. By performing this press forming operation in parallel with the retracting slide operation, the metal blank 1 is formed into the panel 2 having a concave shape by the die 20 and the punch 10.

[0038] Here, with reference to FIG. 7, the movement of the cam slider 53 and the cam driver 55 from the completion of the second step S102 to the completion of the third step S103 will be described.

[0039] First, the cam driver 55 descends from the third position Q3 to the fourth position Q4 shown in FIG. 5(d) by the cam driving unit 57. At this time, the first cam surface 55a of the cam driver 55 slides on the first cam surface 53a of the cam slider 53, and the second cam surface 55b of the cam driver 55 slides on the second cam surface 53b of the cam slider 53. Further, the lower part of the cam driver 55 enters the recess 56a of the cam base 56.

[0040] Subsequently, the cam driver 55 descends from the fourth position Q4 to the fifth position Q5 shown in FIG. 5(e) by the cam driving unit 57. At this time, the first cam surface 55a of the cam driver 55 slides on the first cam surface 53a of the cam slider 53, and the second cam surface 55b of the cam driver 55 slides on the second cam surface 53b of the cam slider 53. At the fifth position Q5, the inclined portion 55b1 of the second cam surface 55b of the cam driver 55 abuts on the inclined portion 53b1 of the second cam surface 53b of the cam slider 53. The fifth position Q5 at this time corresponds to the "inflow start position" where the inflow of the material of the metal blank 1 to the die 20 side is started.

[0041] The cam driver 55 subsequently descends from the fifth position Q5 to the sixth position Q6 shown in FIG. 5(f) by the cam driving unit 57. The cam driver 55 slides the cam slider 53 from the second position R2 to the first position R1 in the pulling-back direction X2 by sliding its inclined portion 55b1 along the inclined portion 53b1 on the cam slider 53 side. The sixth position Q6 at this time corresponds to the "inflow completion position" where the inflow of the material of the metal blank 1 to the die 20 side is completed. As shown in FIG. 5(f), the second slide amount of the cam slider 53 in the pulling-back direction X2 is d2.

[0042] The fourth step S104 in FIG. 2 is a step of performing the return operation of the die 20. As shown in FIG. 8, in this fourth step S104, the die 20 is moved in the press-forming direction Y from the second lowered position P3 (see FIG. 6) to the initial position P1 by the slide driving unit 42. Thereby, the clamping of the panel 2 is released. Further, due to the upward movement of the die 20, the engagement pin 51a comes out of the engagement hole 52a and the pin engagement is released, and the first member 51 and the second member 52 are separated. Furthermore, in this fourth step S104, the cam driving unit 57 raises the cam driver 55 from the sixth position Q6 (see FIG. 6) to the first position Q1. Although not particularly shown, the movements of the cam slider 53 and the cam driver 55 at this time are opposite to the series of movements from the first step S101 to the third step S103.

[0043] 5. Reduction rate R of the plate thickness of the metal blank 1 As shown in FIG. 9, when the plate thickness reduction rate R of the raw metal sheet 1 is set to 0%, the plate thickness reduction rate R becomes a% (>0%) after the execution of step S102, and further becomes b% (>a%) after the execution of step S103. In step S102, the first slide amount d1 for the tensile slide operation of pulling the end portion 1b of the metal sheet 1 in the tensile direction X1 is preferably preset based on the management reference value Ra after conducting a prior evaluation test. The management reference value Ra is set to a value lower than the limit value of elongation cracking of the metal sheet 1. Thereby, while preventing the occurrence of elongation cracking of the metal sheet 1, the actual plate thickness reduction rate R of the metal sheet 1 can be adjusted to a desired level close to the management reference value Ra. At this time, the closer the management reference value Ra is to the limit value of elongation cracking, the more effective it is in increasing the material yield of the metal sheet 1.

[0044] 6. Operational Effects According to the above-described Embodiment 1, the following operational effects can be obtained.

[0045] In Embodiment 1, first, with the end portion 1a of the metal sheet 1 clamped between the die 20 and the blank holder 30 and the end portion 1b of the metal sheet 1 clamped between the first member 51 and the second member 52, the end portion 1b of the metal sheet 1 is pulled in the tensile direction X1 by the first member 51 and the second member 52. Thereby, the metal sheet 1 is stretched in the tensile direction X1 as a whole due to plastic deformation. Then, with the end portion 1b of the metal sheet 1 still clamped between the first member 51 and the second member 52, the end portion 1b of the metal sheet 1 is pulled back in the pulling-back direction X2 opposite to the tensile direction X1 by the first member 51 and the second member 52. And in accordance with the timing of pulling back the end portion 1b of the metal sheet 1, the die 20 is moved in the press forming direction Y toward the punch 10. Thereby, the metal sheet 1 is formed into a panel by the die 20 and the punch 10.

[0046] According to Embodiment 1, after intentionally stretching the metal blank 1 as much as necessary and possible in the initial stage of forming, substantial press forming can be performed using the die 20 and the punch 10. As a result, compared with the conventional method in which the metal blank 1 is simply stretched as it goes during press forming, the metal blank 1 can be stretched in the initial stage of forming by effectively using the extra elongation margin, and the thickness reduction rate R of the metal blank 1 can be increased. Therefore, the panel 2 after press forming can be enlarged for a metal blank 1 of a predetermined size, or the size of the metal blank 1 for obtaining a panel 2 of a predetermined size can be reduced. Thereby, the material yield of the metal blank 1 is improved compared with the conventional method.

[0047] As described above, according to Embodiment 1, it becomes possible to improve the material yield of the metal blank 1.

[0048] Further, according to Embodiment 1, by making the first slide amount d1 and the second slide amount d2 of the first member 51 and the second member 52 coincide, the control related to the slide of the first member 51 and the second member 52 can be simplified.

[0049] Further, according to Embodiment 1, by setting the first slide amount d1 of the first member 51 and the second member 52 based on the management reference value Ra of the thickness reduction rate R of the metal blank 1, the actual thickness reduction rate R of the metal blank 1 can be adjusted to a desired level.

[0050] (Embodiment 2) Embodiment 2 is different from Embodiment 1 in that the die 20 is moved in the press forming direction after the slide in the pulling-back direction X2 of the first member 51 and the second member 52 is completed. In Embodiment 2, the press forming method shown in FIG. 10 can be used.

[0051] Steps S201, S202, and S204 in FIG. 10 are the same as steps S101, S102, and S104 (see FIG. 2) in Embodiment 1. Step S203 is a step of performing a retracting slide operation of the first member 51 and the second member 52 before performing the press forming operation of the die 20. Step S203A is a step of performing the press forming operation of the die 20 after the completion of the retracting slide operation of the first member 51 and the second member 52.

[0052] The above press forming method can be implemented using the press forming apparatus 101 of Embodiment 1. Alternatively, the processing corresponding to the steps from step S201 to step S203 and the processing corresponding to the steps from step S203A to step S204 may be implemented by separate apparatuses.

[0053] According to Embodiment 2, after the end portion 1b of the metal blank 1 is retracted in the retracting direction X2 while being sandwiched between the first member 51 and the second member 52, the metal blank 1 can be formed into a panel by the die 20 and the punch 10.

[0054] The present invention is not limited to only the above-described typical forms, and various applications and modifications can be considered without departing from the object of the present invention. For example, the following various forms applying the above-described form can also be implemented.

[0055] In the above-described form, the case where the first slide amount d1 in the pulling direction X1 and the second slide amount d2 in the retracting direction X2 of the first member 51 and the second member 52 are made the same is illustrated. However, if necessary, the first slide amount d1 and the second slide amount d2 may be made different.

[0056] In the above-described form, a cam structure that slides the first member 51 and the second member 52 by utilizing the lifting and lowering operation of the cam slider 53 that slidably contacts the cam slider 53 is illustrated. However, the structure for sliding the first member 51 and the second member 52 is not limited to this, and other cam structures, crank structures, etc. can be appropriately adopted.

Explanation of Reference Numerals

[0057] 1…Metal base plate, 1a, 1b…Both ends, 1a…One end (end), 1b…The other end (end), 2…Panel, 10…Punch, 20…Die, 20a, 20b…Both ends, 30…Blank holder, 40…First drive mechanism part, 50…Second drive mechanism part, 51…First member, 52…Second member, 60…Control part, 101…Press forming device, d1…First slide amount, d2…Second slide amount, R…Sheet thickness reduction rate, Ra…Management reference value, S101~S104, S102~S204…Press forming method, X…Width direction, X1…Tensile direction, X2…Return direction, Y…Press forming direction

Claims

1. A press forming method for forming a metal sheet into a panel, comprising: using a punch, a die provided opposite to the punch, a blank holder provided opposite to both end portions in the width direction of the die, a first member slidably provided on the die in the width direction, and a second member slidably provided on the blank holder in the width direction; with one end portion of both end portions of the metal sheet sandwiched between the die and the blank holder and the other end portion sandwiched between the first member and the second member, sliding the first member and the second member integrally in the tensile direction and then sliding them in the pulling-back direction opposite to the tensile direction, and moving the die in the press forming direction toward the punch in parallel with the sliding of the first member and the second member in the pulling-back direction or after the sliding in the pulling-back direction is completed to form the metal sheet into the panel with the die and the punch.

2. The press forming method according to claim 1, wherein a first slide amount in the tensile direction of the first member and the second member is the same as a second slide amount in the pulling-back direction.

3. The press forming method according to claim 2, wherein the first slide amount is set based on a management reference value of a sheet thickness reduction rate during press forming of the metal sheet.

4. A press forming apparatus for forming a metal sheet into a panel, comprising: a punch; a die provided opposite to the punch; a blank holder provided opposite to both end portions in the width direction of the die; a first drive mechanism unit for moving the die in the press forming direction; a first member slidably provided on the die in the width direction and a second member slidably provided on the blank holder in the width direction, and a second drive mechanism unit for sliding the first member and the second member integrally in the tensile direction and then sliding them in the pulling-back direction opposite to the tensile direction with one end portion of both end portions of the metal sheet sandwiched between the die and the blank holder and the other end portion sandwiched between the first member and the second member; a control unit for controlling the first drive mechanism unit and the second drive mechanism unit; and comprising. The press forming device is such that the control unit moves the die toward the punch in the press forming direction by the first drive mechanism unit in parallel with or after completion of the slide of the first member and the second member in the pulling-back direction by the second drive mechanism unit, and forms the metal sheet into the panel with the die and the punch.

5. The press forming device according to claim 4, wherein a first slide amount in the pulling direction of the first member and the second member is the same as a second slide amount in the pulling-back direction.

6. The press forming device according to claim 5, wherein the control unit sets the first slide amount by the second drive mechanism unit based on a management reference value of a sheet thickness reduction rate during press forming of the metal sheet.

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